Get a basic computer. Even if it doesn't last long, replacing $10 - $15 isn't that big of a deal. All the other data that can be tracked by fancy computers won't matter if you don't know how to use it.

After riding for a couple of years, I plateaued - no matter how much effort I put in I wasn't improving - and I refused to believe I was riding to my potential. I worked with a coach for a couple of months and she showed me how much better I can be on long rides if I increased my cadence (I didn't realize it but my average was around 70 rpms). Since then, I could care less about most stuff on the computer while I'm riding - I really focus on cadence and heart rate. I now know a HR range that works really well for me on long rides - and I know when to ignore my HR monitor, too. I also use the timer and lap functions a lot for intervals and for comparing ride segments.

Most of the information on how to best use cadence, HR, etc. data is available in books, but I found working with a coach the best $400 I've spent on cycling so far. So I got a computer that could track all that for me. The first (and second) was a Sigma - not recommended. It didn't like it when it was cold, it didn't like getting wet (and I would sweat all over it even on dry days), not a reliable computer at all. I'm using a Garmin 500 now, we'll see how it goes.

JB